TIMELINE-Soccer-Key events in growth of Major League Soccer

March 5 (Reuters) - Major League Soccer (MLS) will begin its 20th season on Friday. Here is a timeline of key events in the growth of the league:

1988 - As part of the deal for the United States to host the 1994 World Cup, the U.S. Soccer Federation agreed to create a fully professional soccer league. MLS was formally created in February 1995.

1996 - MLS began its first season with 10 teams. The opening game was held on April 6, 1996 and featured the San Jose Clash against D.C. United. United won the first MLS Cup with a 3-2 win over the LA Galaxy in front of 34,643 fans at Foxboro Stadium in New England. DC won three of the first four MLS Cups.

1998 - The first expansion moves saw the league grow to 12 with the addition of the Chicago Fire and Miami Fusion.

1999 - Former NFL executive Don Garber was appointed the league's second commissioner, replacing Doug Logan. Garber moved to eliminate some of the league's quirky rules and bring the regulations of the game on the field more closely in line with international norms.

2002 - With the league losing money, reportedly $250 million in the first five years, the Tampa and Miami teams were closed down and the league returned to a 10-team structure.

2005 - With attendances rising and interest in the game boosted by a last-eight finish for the U.S in the 2002 World Cup finals, the league began to grow again with the addition of Real Salt Lake and a second team in Los Angeles - Chivas USA.

2007 - MLS moved into Canada for the first time with Toronto FC joining the league. Despite rumours that FIFA would be unhappy with a league crossing borders, there was no dissent from the governing body.

2007 - LA Galaxy pulled off the biggest signing in the history of the league when they brought former England and Manchester United midfielder David Beckham from Real Madrid on an MLS record $6.5 million annual salary. To facilitate the deal, MLS introduced the 'Designated Player' rule which allows for star players to be paid mostly from outside of the salary cap.

2009 - The Seattle Sounders, closely aligned with NFL team the Seattle Seahawks, joined the league and broke records for attendances with a season average of 30,942.

2010 - Former France and Arsenal striker Thierry Henry was signed by the New York Red Bulls while another new team, the Philadelphia Union, joined the league.

2011 - Following the huge success in Seattle, the league expanded to two further Pacific North West markets with the Vancouver Whitecaps and Portland Timbers both joining - the latter creating the league's most noted derby game with Seattle.

2012 - A third Canadian club joined the league with the addition of Montreal Impact, who signed Italian internationals Marco Di Vaio and Alessandro Nesta.

2014 - MLS signed a new television deal, reported to be worth $750 million over eight years with ESPN, Fox Sports and Spanish language network Univision.

2015 - New York City FC, majority owned by Manchester City, and Orlando City, with Brazilian backing, joined the league. Spain international David Villa signed with NYCFC with England's Frank Lampard set to join later in the year. Brazil international Kaka signed for Orlando and former England and Liverpool captain Steven Gerrard agreed a move to LA Galaxy. (Compiled by Simon Evans in Washington; Editing by Mark Lamport-Stokes)